In some communication systems in which a plurality of communication devices are located, communication devices having high communication processing performance and communication devices having low communication processing performance are both present. In such communication systems, when a low-performance communication device receives broadcast frames, packet drop is likely to occur. It is therefore difficult to include communication devices having different communication performances in a communication system.
In the optical communication system described in Patent Literature 1, a station communication device includes a first subscriber communication device that performs low-speed communication and a second subscriber communication device that performs high-speed communication, and the communication speed with an external network is higher than that of the first subscriber communication device but lower than that of the second subscriber communication device. The station communication device acquires delivery request signal information indicating a multicast signal that a terminal of the first subscriber communication device requests delivery of, and it then transfers the multicast signal to the second subscriber communication device without any condition. In addition, the station communication device transfers the multicast signal to the first subscriber communication device in response to the delivery request signal information. In this manner, the optical communication system described in Patent Literature 1 achieves efficient use of communication bands.